1. Field of the Invention
The present invention relates to an image encoding apparatus and an image encoding method, which encode image data into encoded data.
2. Description of the Related Art
In a prior-art image encoding apparatus, a plurality of partial regions (hereinafter referred to as “pattern images”) are cut out of an input image. Position information of the cut-out pattern images is extracted, and the pattern images are individually encoded. Alternatively, the plural pattern images are simply gathered and treated as a single image, and the single image is encoded. Using synthesis image data of the pattern images and the position information of the pattern images, encoded data is generated.
In “Pattern Dictionary” or “Symbol Dictionary”, as disclosed in ISO/IEC 14492, pattern images that are cut out of an input image are subjected to a similar process that is named “Symbol instance bitmap”.
The prior-art encoding method, however, has the following drawback.
In the prior-art encoding method, pattern images are gathered and encoded. In this method, the pattern images are simply cut out, the pattern images are simply gathered and treated as a single image, and the single image is encoded. No consideration is given to the shapes of the pattern images, and the efficiency in encoding is low.